Originally Posted by
bikingshearer
The photos give further credence to a very reliable source (won't say who) who told me that Ciocc made his frames with teh same wheelbase regadless of other dimensions, the result being, as the frame gets larger and larger, the head angle gets steeper and steeper and the tide gets twitchier and twitchier.
My source said a 64cm Ciocc was downright scary to ride - I don't even want to think about this one.
Sounds like the same approach Albert Eisentraut took on his "production" bikes back in the 80's, but with VERY different results. My 63cm Eisentraut "Rainbow" has a 98cm (38.5") wheelbase and 74.5 deg head angle. Solid as a rock, regardless of speed (well, up to 50mph/80kph, anyway - never went faster than that). Albert was well known for mixing tube sets for best results. That may have been part of the problem with CIOCC - Columbus tubing was pretty limited back then: SL or SP. Period. Also, every big CIOCC I've seen had a way steep seat angle (74ish degrees). That'd put the rider WAY too far forward for good handling. My Rainbow has a seat angle of 72 deg, and I usually ran the saddle all the way back on it.
BTW, I've ridden big bikes with more "normal" head angles (72-73 deg) and it feels like I'm pushing a shopping cart, not riding a bike - almost like the front wheel is in a different time zone. Also that tends to make the front end too light, and suceptible to washing out. Not a good thing at high speed.
In short, building a big frame that works is tricky, and there aren't many builders who are good at it. IMO, Eisentraut is one who is good, Pellizzoli (CIOCC) isn't.
SP
Bend, OR
ps - in case anybody asks, I've been riding "seriously" for 35 years, and spent 7 years wrenching professionally, including a stint as service manager/pro-bike specialist at one of Seattle's top bike shops, so I've had the chance to ride "a few" good bikes.